骨髓增生异常综合征的免疫表型特征分析

 【摘要】　目的　评价免疫表型在骨髓增生异常综合征（MDS）诊断中的价值。方法　采用流式细胞术对27例MDS患者的骨髓细胞进行免疫表型检测。结果　随着MDS疾病的进展,CD+34细胞比例逐渐升高,分别为：难治性贫血／环形铁粒幼细胞性难治性贫血（RA／RAS）7.43 %,难治性贫血伴原始细胞增多（RAEB）36.81 %,难治性贫血伴原始细胞增多转化型（RAEB-T）56.45 %,3组差异有统计学意义（F＝51.197,P＝0.000）,且各组间差异均有统计学意义（P＜0.05）;髓系抗原CD33、CD13、HLA-DR表达逐渐增高,CD14、CD15抗原表达随着疾病的进展逐渐降低,3组间差异有统计学意义（P＜0.05）;B淋巴细胞表面抗原CD19、CD10的表达随着疾病进展而降低;T淋巴细胞表面抗原CD7表达随着疾病进展而增高,分别为RA／RAS 2.63 %、RAEB 10.79 % 和RAEB-T 11.00 %,3组间差异有统计学意义（F＝10.439,P＝0.001）,其中RA／RAS组与RAEB组、RAEB-T组之间差异有统计学意义（P＝0.000,P＝0.001）。结论　检测MDS患者骨髓细胞的免疫表型有助于MDS的诊断、分型和判断预后,从而为治疗提供依据。     

Expression of p53, bcl-2 and ras oncoproteins and apoptosis levels in acute leukaemias and myelodysplastic syndromes.

We analysed by immunocytochemistry the expression of p53, bcl-2 and ras proteins in bone marrow blasts from 59 patients with acute leukaemia (AL), 36 myeloid (AML) and 23 lymphoid (ALL), and from 22 patients with myelodysplastic syndrome (MDS); our aim was to examine if abnormalities in their expression were associated with peculiar biological and clinical findings, or with an altered apoptosis rate, as measured by TUNEL technique. The oncoproteins were expressed with extreme variability, without significant differences among the various morphological or immunological AL subtypes. The mean percentages of bcl-2+ blasts were significantly higher in AML than in MDS (p = 0.01), and in MDS with bone marrow blastosis than in the forms without excess of blasts (p = 0.007). The lowest percentages of apoptotic cells were observed in ALL (mean 1%, p = 0.006), whereas in MDS the apoptotic index was higher (16.7%) than in AML (8.6%) and than in the normal controls (10.8%). but the difference tended to be statistically significant only for cases of refractory anaemia. Whereas in AML and MDS the apoptotic rate was independent of the oncoprotein expression, in ALL there was a significant linear relationship between TUNEL and ras positivity (p = 0.01). Among AML patients treated with intensive polychemotherapy, no differences were observed in oncoprotein expression and apoptotic rate between responders and resistant cases. In conclusion, our data are in agreement with the hypothesis that decreased apoptosis and enhanced cell survival are associated with AL, whereas a high level of apoptosis may be responsible for the ineffective hematopoiesis in MDS; abnormal expression of oncoproteins, even if not strictly related to apoptosis level, may influence disease behaviour.     

潜在的癌症治疗靶点:癌蛋白CIP2A

蛋白磷酸酶在细胞的生命活动中起着关键作用,其中蛋白磷酸酶2A(protein phosphatase 2A,PP2A)可抑制多个关键致癌信号通路的活性,是一种重要的肿瘤抑制因子。因此,抑制PP2A的活性是人体正常细胞转化为癌细胞的条件之一。PP2A的癌性抑制剂(cancerous inhibitor of protein phosphatase 2A,CIP2A)是恶性肿瘤细胞中PP2A的内源性抑制剂,它的异常表达可导致PP2A失活。多项研究已证实了CIP2A在促进肿瘤生长、抗凋亡和肿瘤衰老诱导疗法中的作用。值得注意的是,高水平的CIP2A预示着多种癌症患者的预后不良。癌蛋白MYC(PP2A去磷酸化调节的癌蛋白之一)第62位丝氨酸的磷酸化水平可指示CIP2A的致癌活性。CIP2A和MYC之间的正反馈通路提高了MYC在癌细胞中的活性。此外,CIP2A还可提高其他癌蛋白的磷酸化水平及其活性,包括E2F1、AKT和mTORC1。然而,CIP2A对于正常小鼠的生长发育并不是必不可少的。这些研究结果表明,在癌细胞中靶向CIP2A进而重新激活PP2A不失是一种癌症靶向治疗的新策略。本文将对靶向CIP2A的肿瘤治疗方法及其可行性进行讨论。     

Megakaryocytopoiesis and apoptosis in patients with myelodysplastic syndromes

In order to investigate simultaneously the megakaryocytopoiesis and apoptotic characteristics in bone marrow in patients with myelodysplastic syndromes (MDS), we used CD41 immunoenzyme (alkaline phosphatase anti-alkaline phosphatase) and DNA in situ end-labeling techniques on plastic embedded bone marrow biopsy sections of 29 MDS patients. Fourteen patients with iron deficiency anemia served as controls. The results showed that CD41-positive cells in MDS marrow numbered 26.2 +/- 18.2/mm2 (mean +/- standard deviation) compared with 15.6 +/- 7.1/mm2 in controls (P < 0.05). Numbers of cells with the morphology of micro-megakaryocytes in MDS marrow were significantly higher than in controls (P < 0.01). Furthermore, megakaryocytes in MDS marrow were frequently distributed along trabeculae (in 27 cases) and formed clusters (in 25 cases). Apoptotic megakaryocytes in MDS marrow accounted for just 4.4 and 9.3% of all CD41-positive cells and all apoptotic cells, respectively (P > 0.05 compared with controls), but apoptosis occurred only in micro-megakaryocytes. Based on these observations, we conclude that megakaryocytosis and dysmegakaryocytosis are the features of dyshematopoiesis in MDS marrow. Decreased thrombocyte production and thrombocyte release coming from increased dys(micro)megakaryocytes and abnormally located megakaryocytes perhaps play a more important role in peripheral thrombocytopenia than megakaryocytic apoptosis itself. Apoptosis of micro-megakaryocytes may be a protective biological mechanism to remove useless megakaryocytes.     

骨髓增生异常综合征造血细胞bcl-2 VEGF抗原表达及原位凋亡的研究

  目的  研究骨髓增生异常综合征(MDS)bcl-2、VEGF抗原表达及造血细胞原位凋亡之间的关系, 探讨MDS发病机理。  方法  对MDS患者骨髓活检标本光镜下观察骨髓增生程度、各系造血细胞形态异常情况、不成熟前体细胞异常定位(ALJP)等组织病理学改变, 免疫组织化学染色观测bcl-2及VEGF抗原的表达, TUNEL法检测造血细胞原位凋亡。  结果  13例患者骨髓均有不同程度的异常造血, 异常造血主要累及的细胞系列不尽相同, RA、RAEB两组患者异常造血未见明显区别; 有6例患者检出ALIP现象, 其中RA 3例(3/8, 37.50%), RAEB 3例(3/5, 60.00%); VEGF阳性者占9例(9/13, 69.23%), 其中RA 6例(6/8, 75.00%), RAEB 3例(3/5, 60.00%); bcl-2阳性者占7例, 其中RA4例(4/8, 50.00%), RAEB 3例(3/5, 60.00%); TUNEL检测13例患者均为阳性, 检出ALIP现象者, 其造血细胞发生原位调亡明显, 而bcl-2、VEGF与TUNEL结果之间未见明显关联。  结论  MDS患者均存在不同程度的细胞凋亡异常, 而TUNEL法提供了简便、实用、敏感、快速特异的检测MDS细胞原位凋亡的方法结果初步显示MDS患者ALlP现象明显者其细胞凋亡也明显, 提示调控MDS患者细胞凋亡和恶性克隆增殖可能是两种完全不同的机制。      

PP2A inhibition determines poor outcome and doxorubicin resistance in early breast cancer and its activation shows promising therapeutic effects

The protein phosphatase 2A (PP2A) is a key tumor suppressor which has emerged as a novel molecular target in some human cancers. Here, we show that PP2A inhibition is a common event in breast cancer and identified PP2A phosphorylation and deregulation SET and CIP2A as molecular contributing mechanisms to inactivate PP2A. Interestingly, restoration of PP2A activity after FTY720 treatment reduced cell growth, induced apoptosis and decreased AKT and ERK activation. Moreover, FTY720 led to PP2A activation then enhancing doxorubicin-induced antitumor effects both in vitro and in vivo. PP2A inhibition (CPscore: PP2A phosphorylation and/or CIP2A overexpression) was detected in 27% of cases (62/230), and associated with grade (p = 0.017), relapse (p < 0.001), negative estrogen (p < 0.001) and progesterone receptor expression (p < 0.001), HER2-positive tumors (p = 0.049), Ki-67 expression (p < 0.001), and higher AKT (p < 0.001) and ERK (p < 0.001) phosphorylation. Moreover, PP2A inhibition determined shorter overall (p = 0.006) and event-free survival (p = 0.003), and multivariate analysis confirmed its independent prognostic impact. Altogether, our results indicate that PP2A is frequently inactivated in breast cancer and determines worse outcome, and its restoration using PP2A activators represents an alternative therapeutic strategy in this disease.     

Up-regulation of DNA methyltransferases DNMT1, 3A, and 3B in myelodysplastic syndrome

Analyzing bone marrow trephines from (myelodysplastic syndrome) MDS patients we show for the first time strong over-expression of the DNA methyltransferases 1, and 3A (and 3B to a much lesser extent) in the myelodysplastic syndrome FAB subtypes refractory anaemia (RA) and refractory anaemia with excess of blasts (RAEB). The increase in mRNA expression was much less pronounced in refractory anaemia with ringed sideroblasts (RARS). Classification according to the new WHO guidelines revealed distinct differences between RCMD and RARS. This elevated mRNA expression most probably contributes to the frequently found aberrant hypermethylation in MDS and might explain the promising clinical response of MDS patients treated with DNMT inhibitors.     

Clinical implications of blast immunophenotypes in myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are malignant disorders of hematopoietic cells. For many neoplasms, immunophenotype data of the neoplastic cells provide valuable information in clinical practice. However, the clinical values of immunophenotype data have not yet been firmly established for MDS. Since MDS blasts are not predominant in the bone marrow and peripheral blood, which makes reliable immunophenotyping of blasts difficult, we used a newly developed density-centrifugation reagent to generate blast-enriched MDS samples for phenotyping. The key findings of our study, which phenotyped blasts from 116 patients with MDS or acute leukemia transformed from MDS, were the following. (1) MDS blasts were usually CD34⁺CD38⁺HLA-DR⁺CD13⁺CD33⁺CD2^-CD3^-CD5^-CD8^-CD19^-CD20^- in flow cytometric analysis and often lacked myeloperoxidase in cytochemistry, regardless of the MDS subtype. (2) MDS blasts showed asynchronous expression of antigens (expression of both stem cell antigens and antigens of mature myeloid cells). (3) During disease progression of MDS, phenotypic clonal evolution (transition from blasts with a relatively mature phenotype to blasts with a more immature phenotype) occurred in at least some cases. (4) CD7-positivity was an independent variable associated with a short survival in MDS. Further studies of blast immunophenotypes will deepen our understanding of MDS and hopefully improve the clinical approach to these intractable disorders.     

Trisomy 21 as the sole acquired karyotypic abnormality in acute myeloid leukemia and myelodysplastic syndrome

We report five cases of myeloid disorders in which trisomy 21 (+21) was found as the sole acquired karyotypic abnormality, comprising two cases of acute myeloid leukemia (AML) and three cases of myelodysplastic syndrome (MDS). In this series, MDS patients with +21 presented as high grade disease, which included two cases of refractory anemia with excess of blasts (RAEB) and one case of refractory anemia with excess of blasts in transformation (RAEBt), and showed rapid disease progression. Significant thrombocytopenia was observed in all three patients, and bone marrow examination showed a marked reduction in megakaryocytes. AML patients with +21 included one case each of AML-M2 and M4. Despite the poor prognosis reported in AML patients with +21 as the sole abnormality, the patient in our series who was able to complete intensive treatment was cured of disease. The role of +21 in leukemogenesis is reviewed.     

CIP2A mediates erlotinib-induced apoptosis in non-small cell lung cancer cells without EGFR mutation

Background

Epidermal growth factor receptor (EGFR) inhibitors show favorable clinical response in some patients with non-small cell lung cancer (NSCLC) who have no EGFR mutation, indicating alternative mechanisms for their tumoricidal effects. We previously showed erlotinib, a selective EGFR antagonist, inhibited the growth of sensitive hepatocellular carcinoma cells by inhibiting the cancerous inhibitor of protein phosphatase 2A (CIP2A) pathway. The aim of this study was to determine if erlotinib can also inhibit the growth of NSCLC cells by inactivating the CIP2A-dependent signaling pathway.

Methods

Four NSCLC cell lines (H358 H441 H460 and A549) were treated with erlotinib to determine their sensitivity to erlotinib-induced cell death and apoptosis. Expression of CIP2A and the downstream AKT were analyzed. The effects of CIP2A on erlotinib-induced apoptosis were confirmed by overexpression of CIP2A and knockdown of CIP2A gene expression in the sensitive cells and resistant cells, respectively. In vivo efficacy of erlotinib against H358 xenograft tumor was also determined in nude mice.

Results

Erlotinib induced significant cell death and apoptosis in H358 and H441 cells, as evidenced by increased caspase 3 activity and cleavage of pro-caspase 9 and PARP, but not in H460 or A549 cells. The apoptotic effect of erlotinib in the sensitive H358 cells was associated with downregulation of CIP2A, increase in PP2A activity and decrease in AKT phosphorylation. Overexpression of CIP2A and AKT protected the sensitive H358 cells from erlotinib-induced apoptosis. Knockdown of CIP2A gene expression by siRNA enhanced the erlotinib-induced apoptotic in the resistant H460 cells that resembled the sensitive H358 cells. Erlotinib also inhibited the growth of H358 tumors in nude mice.

Conclusions

The CIP2A-dependent pathway mediates the tumoricidal effects of erlotinib on NSCLC cells without EGFR mutations in vitro and in vivo. CIP2A may be a novel molecular target against NSCLC for future drug development.     

CD30 Expression in High-Risk Acute Myeloid Leukemia and Myelodysplastic Syndromes

BackgroundWe assessed for CD30 expression in patients with acute myeloid leukemia (AML) or high-grade myelodysplastic syndrome (MDS) to examine the possibility that anti-CD30 could be targeted therapy in these patients.MethodsMulticolor flow cytometry immunophenotypic analysis was performed on bone marrow aspirates of 135 patients with AML or MDS and peripheral blood samples in a subset of 33 patients. Immunohistochemistry was performed on bone marrow aspirate clot specimens of 84 patients.ResultsThe median patient age was 63 years (range, 13-92 years); 102 (75%) patients had refractory or recurrent disease, and 68 (50%) had high-risk cytogenetics. Overall, the median percentage of blasts positive for CD30 was 14% (range, 0%-91%). By using an arbitrary 20% cutoff, 49 (36%) patients were considered to have CD30 expression. Monocytic cells, either mature or immature, were consistently negative for CD30. Therefore, CD30 expression was less in AML with monocytic differentiation (P = .006). The patients with persistent disease who had been actively treated had a higher level of CD30 expression than the patients who were untreated (P = .031). In paired samples, CD30 expression was consistently higher in bone marrow blasts than in peripheral blood blasts (P = .002). Immunohistochemistry demonstrated CD30 expression by myeloblasts in a subset of patients, but reactivity was generally weaker and focally compared.ConclusionsCD30 is expressed by myeloblasts in a substantial subset of patients with AML or MDS. Because the study group was composed mostly of patients with high-risk AML or MDS in whom very few treatment options are available, these data raise the possibility that anti-CD30–targeted therapy could be a potential option for this patient group.     

The Wilms' tumor gene WT1 is a good marker for diagnosis of disease progression of myelodysplastic syndromes.

The Wilms' tumor gene, WT1, is a tumor marker for leukemic blast cells. The WT1 expression levels were examined for 57 patients with myelodysplastic syndromes (MDS) (refractory anemia (RA), 35; RA with excess of blasts (RAEB) 14; RAEB in transformation (RAEB-t), six; and MDS with fibrosis, two) and 12 patients with acute myeloid leukemia (AML) evolved from MDS. These levels significantly increased in proportion to the disease progression of MDS from RA to overt AML via RAEB and RAEB-t in both bone marrow (BM) and peripheral blood (PB). WT1 expression levels in PB significantly correlated with the evolution of RAEB or RAEB-t to overt AML within 6 months. Therefore, WT1 expression levels in PB were superior to those in BM for early prediction of the evolution to AML by means of quantitation of the WT1 expression levels. Furthermore, WT1 expression in PB of patients with overt AML evolved from MDS was significantly decreased by effective chemotherapy or allogeneic stem cell transplantation and became undetectable in long-term survivors. These results clearly showed that WT1 expression levels are a tumor marker for preleukemic or leukemic blast cells of MDS and thus reflect the disease progression of MDS. Therefore, monitoring of WT1 expression levels has made continuous assessment of the disease progression of MDS possible, as well as the prediction of the evolution of RAEB or RAEB-t to overt AML within 6 months. The results also showed that quantitation of WT1 expression levels is useful for diagnosis of minimal residual disease of MDS with high sensitivity, thus making it possible to evaluate the efficacy of treatment for MDS.     

Clinical activity and safety of the dual pathway inhibitor rigosertib for higher risk myelodysplastic syndromes following DNA methyltransferase inhibitor therapy

Rigosertib (ON 01910.Na) is an inhibitor of the phosphoinositide 3‐kinase and polo‐like kinase pathways that induces mitotic arrest and apoptosis in neoplastic cells, while sparing normal cells. Our purpose is to summarize the clinical activity and safety of intravenous (IV) rigosertib delivered by an external ambulatory infusion pump in patients with refractory anemia with excess blasts‐1, ‐2, or, ‐t myelodysplastic syndromes (MDS) following prior treatment with DNA methyltransferase (DNMT) inhibitors. A total of 39 patients with MDS who fulfilled these criteria were enrolled in four phase 1‐2 clinical trials of IV rigosertib. Thirty five (88%) had higher risk disease according to the Revised International Prognostic Scoring System. Median overall survival for this group of 39 patients was 35 weeks. Of 30 evaluable patients with follow‐up bone marrow biopsies, 12 (40%) achieved complete (n = 5) or partial (n = 7) bone marrow blast responses. In addition, 15 patients achieved stabilization of bone marrow blasts. One patient with a complete bone marrow response also achieved a complete cytogenetic response. A second patient with stable bone marrow blasts achieved a partial cytogenetic response. Two of the responding patients and three patients with stable disease had hematological improvements. Rigosertib‐induced bone marrow blast decreases and stability appeared to be predictive of prolonged survival. IV rigosertib had a favorable safety profile without significant myelosuppression. Most common drug‐related toxicities included fatigue, diarrhea, nausea, dysuria, and hematuria. In summary, IV rigosertib is well tolerated and has clinical activity in patients with higher risk MDS following DNMT inhibitor treatment. A multinational pivotal phase 3 randomized clinical trial of rigosertib versus best supportive care for patients with MDS with excess blasts following prior treatment with DNMT inhibitors (ONTIME: ON 01910.Na Trial In Myelodysplastic SyndromE) has recently completed enrollment. © 2014 The Authors. Hematological Oncology published by John Wiley & Sons, Ltd.     

Expressions of four major protein Ser/Thr phosphatases in human primary leukemic cells.

Activity and expression of four major protein serine/threonine (Ser/Thr) phosphatases, protein phosphatase type 1 (PP1), protein phosphatase type 2A (PP2A), protein phosphatase type 2B (PP2B) and protein phosphatase type 2C (PP2C) were evaluated in normal peripheral leukocytes, and in various leukemic cells from patients with acute myelogenous leukemia (AML), common acute lymphocytic leukemia (cALL), or chronic lymphocytic leukemia (CLL). PP1 was the most abundant phosphatase in blood cells, and relative abundance of each phosphatase was: PP1 > PP2A > PP2B approximately = PP2C. PP1 activity and its expressions were higher in blasts of AML-M4 and -M5 than in cells of AML-M1, cALL and CLL. PP2A activity and its expression were higher in blasts of AML-M3, -M4 and -M5 than in cells of AML-M1, cALL and CLL. Activity and expression of both PP1 and PP2A in normal monocytes were highest, and PP2A activity in normal neutrophils was lowest among normal leukocytes. PP2B activity and its expression were higher in blasts of AML-M2, -M3 and normal lymphocytes. PP2C activity and its expression were relatively constant in various leukemic cell types. Activities of PP1 and PP2A of AML blasts correlated positively with the expression of CD11b, whereas activities of PP1 and PP2B correlated negatively with the expression of CD7. Thus, each phosphatase was ubiquitously but differently expressed in various leukemic cell types and in normal leukocytes. These data also suggest that expressions of PP1, PP2A and PP2B are relatively low in leukemic blasts arresting at the stage of early pluripotent stem cells, and are differently modulated during the course of myelomonocytic commitment and maturation.     

Expression and activity of caspases 1 and 3 in myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are characterized by abnormal growth of committed progenitors in clonogenic assay, with reduced number of colonies and decreased colony/cluster ratio. It has been suggested that excessive apoptosis is the cause of marrow failure in MDS. We studied the expression of caspase-1 (interleukin-1beta-converting enzyme, ICE) and caspase-3 (CPP32/apopain) in marrow mononuclear cells, and the growth pattern of committed progenitors in a series of 83 MDS cases. The percentage of apoptotic cells as detected by TUNEL technique, and the percentage of caspase-3-positive cells were significantly higher in refractory anemia (RA) and RA with ringed sideroblasts (RAS) than in chronic myelomonocytic leukemia (CMML), refractory anemia with excess of blasts (RAEB) and RAEB in transformation (RAEB-T). Spontaneous growth of CFU-GM was associated with a higher percentage of blasts, and with a lower expression of caspase-3 and caspase-1. The yield of CFU-E, BFU-E, and CFU-GM (in the presence of growth factors) was decreased by comparison to normal marrow, but large individual differences were observed in all cytological categories. Inhibition of caspase-1 and caspase-3 activities by specific inhibitors resulted in a significant increase of the production of all types of colonies (up to 50-fold of control). In the presence of caspase-3 inhibitor, the number of BFU-E and CFU-E was in the range of normal values in most cases of RA and RAS. In addition, caspase-1 and -3 protease activities were detectable by fluorogenic assay in all cases studied. Western blot analysis confirmed the expression of caspase-3, including the cleaved (activated)-p17 form in most cases of RA/RAS analyzed. It is concluded that caspase-3 is implicated in the increased apoptosis observed in MDS and that inhibition of its activity can restore at least partially the growth of committed progenitors.     

Survivin expression in acute leukemias and myelodysplastic syndromes

We analyzed by immunocytochemistry the expression of survivin in bone marrow cells from 36 acute myeloid leukemia (AML) cases, from 98 patients with myelodysplastic syndrome (MDS), and from 41 non hemopathic subjects. Our aim was to evaluate whether abnormalites in survivin expression were associated with peculiar laboratory and clinical findings, altered apoptosis levels or altered proliferative rate. In normal samples survivin was never detectable. It was detected in almost all AML and MDS cases. In AML and in MDS with more than 5% bone marrow blasts survivin levels higher than in RA and RARS were observed (P = 0.04). In MDS a tendential inverse correlation between survivin and TUNEL positivity was identified (P = 0.08), whereas survivin expression was independent of the proliferative rate. Survivin levels did not predict disease progression in MDS; among AML patients treated with intensive polichemotherapy, survivin expression was significantly higher in resistant cases (P = 0.01). Our findings confirm the high incidence of survivin expression in AML. Its abnormal expression also in MDS may play a role in promoting aberrantly increased cell viability and contribute to the altered homeostatic balance between cell growth and cell death.